The Macri government inherited a teetering economy and made things worse by borrowing heavily. Once things went bad, again, the International Monetary Fund compounded the problems with overly optimistic assumptions of the sort made in its Greek rescue efforts.

Weak economic data out of China this week—amid little sign the country is ready to unleash broad-based stimulus—could limit further gains, especially with more tariffs is expected to go into effect Oct. 1.